Posted on 27/06/2023 in Fire Safety 2023
Soybean PIN FR for bio-sourced polymer

Soybean protein dosed with phosphite gave a phosphorus-nitrogen PIN FR effective in bio-sourced PLA polymer. PLA (poly lactic acid) is a widely available bio-sourced polymer but is highly flammable. Soybean protein, naturally rich in nitrogen, was here reacted in water with the simple phosphorus compound dimethyl phosphite (non-classified, widely available) and formaldehyde (bonding agent). The resulting N-P PIN FR enabled PLA to achieve UL 94 V-0 (3 mm) at 7% loading (neat PLA is NR) and reduced pHRR by 15% at 15% loading. The soybean protein based PIN FR increased char formation, reduced flammable gas emission and diluted fire gases by emission of ammonia.

“Facile synthesis of soybean protein-based phosphorus-nitrogen flame retardant for poly(lactic acid)”, L. Dong et al., Polymer Degradation and Stability 214 (2023) 110412

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